from flask_sqlalchemy import SQLAlchemy
from flask_socketio import SocketIO
from flask_cors import CORS
from flask_jwt_extended import JWTManager

# 初始化扩展实例
db = SQLAlchemy()
socketio = SocketIO()
cors = CORS()
jwt = JWTManager()

__all__ = ['db', 'socketio', 'cors', 'jwt']